Patent Document 1 (JP-A-2014-20678) is disclosed as background art in this technical field. A heat exchanger disclosed in PTL 1 is a fin and tube heat exchanger including a heat-transfer tube having a part composed of four or more paths, in order to prevent degradation of heat exchanger performance of the heat exchanger even if a refrigerant, whose temperature is significantly changed during heat release, is used. Respective paths have substantially parallel flow of the refrigerant in a stage direction, and, further, refrigerant inlets of the paths are positioned to be substantially adjacent in a case of being used as a radiator. In this manner, the description is read that it is possible to reduce the degradation of heat exchange performance, without an increase in draft resistance of an air-side circuit and an increase in manufacturing cost (refer to Abstract).
In addition, Patent Document 2 (JP-A-2011-145011) is disclosed. In order to provide an air conditioner in which a melted residue of frost is removed and it is possible to achieve high-performance heating capacity at a low cost, an air conditioner disclosed in Patent Document 2 is an air conditioner that includes a refrigeration cycle in which at least a compressor, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger are connected using a refrigerant circuit. The outdoor heat exchanger is composed of systems of refrigerant flow paths. Any inlets of the systems of refrigerant flow paths are positioned in a refrigerant flow pipe on the second stage from the uppermost stage or the uppermost stage of the outdoor heat exchanger when the outdoor heat exchanger is used as an evaporator. In this manner, the description is read that it is possible to achieve such an air conditioner (refer to Abstract).